Many different materials have been investigated to resist non-specific protein adsorption. Chemistries utilized for this purpose include polyethers (e.g., polyethylene glycol in particular), polysaccharides such as dextran, hydrophilic polymers such as polyvinylpyrrolidone or hydroxyethyl-methacrylate, heparin, intramolecular zwitterions or mixed charge materials, and hydrogen bond accepting groups such as those described in U.S. Pat. No. 7,276,286. The ability of these materials in preventing protein adsorption varies greatly between the chemistries. Of these materials, only a few resist fouling to the degree required for short-term in vivo application. However, the few materials appropriate for short-term application, when used for longer periods of time in complex media or in vivo, exhibit significant fouling or material degradation, making them unsuitable for long-term applications.
Traditional application of biocompatible coatings, especially those applied to medical device substrates, is performed by dip coating the substrate in a single polymer solution. For hydrophilic polymers applied to hydrophobic substrates, this approach presents many challenges as it can be difficult to form stable coatings. In an attempt to improve stability, hydrophilic materials have been cross-linked or copolymerized with hydrophobic groups. However, such approaches can have significant negative effects on the overall coating performance, especially when resistance to protein adsorption is desired.
There exists a need for coating formulations that overcome the limitations described above.
Therefore, it is an object of the invention to provide non-fouling coating formulations where an undercoating functionalized substrate is used to promote adhesion of a top coating onto a substrate surface and methods of making and using thereof.